Power hammer



AprlS, 1966 R. FERWERDA 3,244,241

POWER Filed March 11. 1963 4 Sheets-Sheet 1 jfl-gi- April 5, 1966 R. FERWERDA 3,244,241

POWER HAMMER Filed March 11, 1963 4 sheets-sheet z 4s r=| a r=1 r l y 4f |-l I 42 44a ish 1N VEN TOR. Hw F57? wen# y April 5, 1966 R. FERwi-:RDA 3,244,241

POWER HAMMER Filed March l1, 1963 4 Sheets-Sheet :5

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pril 5, 1966 Filed March 11. 1963 R. F ERWERDA POWER HAMMER 4 SheetsS'heet 4.

United States Patent() 3,244,241 POWER `HAMMER Ray-Fervverda, 1050 NW. 163ml Drive, North Miami, Fla. Filed Mar. 11, 1963, Ser. No. 264,253 4 Claims. (Cl. 173-105) This invention relates to improvements in a power actuated blow delivering device of a very powerful character generally used las a power hammer or a power chisel, a power ram or the like.

One of the objects ofthe present invention is to provide a self-contained blow delivering'device comprising a housingmeans with a tool carrying member extending into the housing means at one end, generally the lower end, and with an anvil lying insideof the housing and adapted to deliver a blow to a tool carrying member when struck by the hammer. The hammer is reciprocatably mounted in the housing means for movement to- `warfd and away from the anvil, the blow being delivered by a powerful helical spring surrounding ahamrner eX- tension and engaged between the hammer and a portion of the housing means and Valways urging the hammer to- 'Ward the anvil. Power means is carriedibythe housing means and constructed and arranged to engage the end of a hammer extension remote from the hammer,usually 'at the'upper end thereof, and tolift the hammer so as to compress the spring and thereafter to suddenly release the hammer extension, whereby the spring then drives the hammer with gre-at force against the anvil to deliver a blow to the'tool. Y Another object of the present invention-is to provide the 4above described devicein such simple form that there are few moving parts which are very rugged and adapted for a long period of etlici'ent operation without repairs and adapted to deliver blows more powerful and more rapidly repeated than by presently known conventional methods.

Other objects and advantages of the present invention will be set forth in the accompanying drawings and specication and the essential yfeatures thereof will be sumrnarized in the appended claims.

In the drawings- FIG. 1 is a central sectional view through one embodimentof the device of this invention, together with means for mounting the device on a boom carrying vehicle adapted to hold and manipulate theblow actuating device;

FIG. 1A is a continuation 4of'FIG. -l at vthelower end thereofshowing the tool carrying 'member located below the line A indicated in both iig-ares;

FIG. 2 is a section-al View, enlarged, taken along the FIG. 3 is a sectional view taken along the line l3 3 of FIG. l;

FIG. 4 is a fragmental sectional view taken along the line 4 4 of FIG. 2;

FIG. 5 is a fragmental sectional view taken along the line 5*5 of FIG. 2;

i FIG. 6 is a `sectional view taken along the line 6-6 of FIGS. y2 and 5;Y while u FIG. 7 is a View similar `to a portion of FIG. 1, 'showing powermeans for turning the tool 46 responsive to remote control.

Referring to FIG. 1, this improved blow-delivering device is compactly assembled in connection with a'housing `means which comprises a cylindrical member 10 carrying at its upper end rigid therewith aange 10a which is secured by means of screws or bolts 11 to a housing means head 12. The cylinder 10 is 'provided with a head member 13 at the lower end thereof welded to the cylinder 10 and having a central opening through which vantage of 20"to '1.

3,244,241 Patented Apr. 5, 1966 ICC Venters an anvilV shaft 14coaxial with the cylinder 10 and carrying integral therewith at its upper end the anvil 14a. The anvil shaft 14 passes through a suitable bearing sleeve 15 which is rigidly connected to the head 13 and cylinder 10 by means of gussets 16 welded in place. iPreferably, a recoil absorbing cushion 17 is provided in the form of a rubber doughnut surrounding the anvil shaft 14 and lying against the head 13. I have found that about durometer rubber is satisfactory for this cushion. `It will be noted that the anvil shaft 14 is freely slidable axially of the cylinder l10.

A hammer 18 is provided for delivering a blow to the anvil. This hammer is axially aligned Ywith the anvil and is provided with a hammer extension 19 extending axially upwardly thro-ugh the cylinder 10 and out the upper end vthereof through a sleeve bearing 20 which is held in the proper position by means of a bearing cap `21 to which 'the bearing is wel-ded land the'cap in turn is secured to the lower 'wall of the hou-sing head portion 12 by means of screws or bolts 22. An oil seal 20a prevents leakage of lubricant out of housing means 12. A powerful helical spring 23, approximately one foot in diameter and about three feet long (for a 4-ton blow) surrounds the hammer extension 19 within the cylinder 10 for compression between the hammer 18 andbearing cap 21 which lies against the lower wall of the-housing head po-rtion 12. Preferably each end of spring 23engages va disc 23a of a hard, high abrasion resistant plastic backed up by a rubberlike cushion 23h.

Means is'provided at the upper end of the hammer extension 19 whereby it may be lifted by power actuated means to provide periodic blows- This comprises a T-shape member 24, clearly shown in FIGS. 1, 2, 5 and 6, having a vertically extending central lbore which fits on a reduced diameter portion 19a ofthe hammer extension which terminates at a Shoulder 19t against which the T-shape member 24 rests. The upper portion of 19a is threaded and a nut 25 holds the member -24 in position. The T-shape member has laterally extending "arms 24a on opposite sides thereof for the purpose of engagement by the device about to be described.

Preferably a space of a few thousandths of an inch is provided at 71, FIG. 6, between 19a and 24. Also, preferably a shoulder 72 keeps nut 25 from engaging tight against 24 leaving a few thousandths of an inch space at 73. This permits member 24 to accommodate to twisting of hammer extension 19 when spring 23 is stressed.

The power means for lifting the hammer extension comprises a hydraulic motor 26 bolted to the wall of the housing head means 12 and supplied with hydraulic power through flexible tubular connections 27 and Q8 from any suitable source. This motor terminates in a drive shaft 29 which extends verticallydownwardly into the housing means portion 12 -and is provided with 'suit- 'a'b'le bearings -such as 30 carried by the bearing cap 31 and :bearing 32 ycarried |by the bearing cap 33 '(FIG. 4). Rotatable with's'haft 29 is a Vworm '-34 which meshes with a cone drive worm gear 35 vwith a mechanical gad- Re'ferring to'FIGS. 2 fandf4, the wormj'gear 35 is keyed toa yshaft 36 which in kturn is journal'e'd in bearings 37 carried by suitable bearing caps "38 which are secured to the housing head 12. Keyed to the shaft 36 are-a` pair of pinions '39 each of which is aligned with a gear wheel 40 Vmeshing with the pinions '39 and having a mechanical ladvantage of approximately 3 'to l. Each of the gear wheels 40'is keyed to -a shaft 4'1 which is jou-rnaled in suitable bear-ings 42 which are "carried by bearing -caps 43 lsuitably at-tached to the -housing head Vportion-12. A -pair of cam rollers 44 `are `secured to `each of the gear Wheels 40 diametrically opposite eachother by means of stub shafts `44a which extend through their respective'gearlwheels and are held in posi- 3 tion by nuts 45 and suitable lock washers. Each of the cam rollers 44 is rotatably mounted on its associated stub shaft. The cam rollers 44 on each gear wheel are aligned to engage beneath the opposite -arms 24a of the T-member 24 so as to lift the hammer extension 19 and the hammer head 18. It will be noted in FIG. 1 that each cam roller 44 in the dotted line position of FIG. 1 engages beneath one of the T-shape arms 24a toward the left side thereof and lifts the T-shape member while the cam roller 44 moves through an -arc of slightly more than 90 causing the cam roller to reach the dot-dash position of FIG. l after which it rolls out of contact with the arm 24a in the dot-dash position, thus releasing the arm suddenly so that it is urged downwardly impelled by spring 23 which has been compressed approximately 10 inches of its vertical length.

As s-hown in FIG. 1A, the anvil shaft 14 provides a tool carrying member. In this view the tool 46 has a central bore 46h provided axially of its upper end. Into this bore extends a projecting portion of shaft 14 which is held in position by means of one or more pins 47 embedded part way in the tool and part way in the shaft 14 and held in position by a sleeve 48 which embraces the sh-aft 14 at its lower end and rests upon the shoulder 46a of the tool. This prevents the escape of the attaching pins 47.

The tool shown at 46 is a chisel point Itool for cracking rock, slate, concrete, masonry and many other const-ruction materials. However, this tool might be a bull point for breaking up concrete and cement, or frost chisel for breaking away a frost layer of earth, or a tamper head for providing power compacting blows for tamping eart-h to solidify the same, or it might be a pile driver head for driving posts, piling and retainers into the ground. In other words, any suitable tool adapted to be dr-iven by blows of the hammer 18 may be 4attached to this device.

Stop means is provided on the anvil shaft 14 to prevent it being driven up inside of the cylinder so that the anvil head 14a always remains spaced from the blow delivering hammer 18. This stop is shown at 49 and comprises a split collar threaded on the shaft `14 Aand held in position by bolt 50. This collar will strike the lower end of the bearing sleeve on the rebound after a blow is delivered and stop the upward motion of the anvil member 14a. Preferably, but not necessarily, a recoil spring 51 is provided surrounding the shaft 14 and held between the collar 49 and the bearing 15 to cushion the recoil of the bounce after the blow is delivered.

The collar 49 may be provided with means for preventing rotation of the tool 46 about its own axis if desired. I have shown in FIG. 1 a bar 52 rigidly welded to the housing cylinder 10 and extending freely through a hole 48a in the collar 49. This holds thetool oriented in a desired position.

As shown in FIGS. l and 3, means is provided for holding my improved blow delivering device and manipulatin-g the same from a boom 53 which may be of any suitable type but is here shown as a telescopic boom of a vehicle show-n in United States Patent No. 2,541,045, granted to Ray and Koop Ferwerda February 13, 1951. Bolted to the free end of this boom are a pair of spaced bearing caps 54, in which is journaled a shaft 55 which carries a -crank arm 55a which in turn -is pivotally connected to a clevis rod 56 which -is controlled by means of a piston 57 reciprocatable in a cylinder 58 secured to the boom 53 by means ofhydraulic uid or the like supplied through conduits 59. Movement of piston 57, which may be controlled from the operators cab, will tilt the device about shaft pivot 55. Welded to the shaft 55 are a pair of spaced parallel ears 60 which in turn are welded to a sleeve 61 in which the cylinder A10 is held snugly but freely reciprocal in a vertical direction `as blows are delivered. To hold the cylinder 10 from rotating in the sleeve 61, a vertical bar 62 is welded to the A flange 10a at t-he top and to a collar 63 atl thebottom which in turn is bolted to the cylinder 10 by bolts 64. Parallel flanges 65 are Welded to the sleeve 61 on opposite sides of the bar 62 and this prevents relative rotation at this point.

In the above described form of this invention, the hydraulic pump unit utilizes between 55 and 65 gallons per minute of fluid at 1250 to 2000 lbs. per square inch pressure and turning at 1800 to 2000 revolutions per minute. The mechanism provides approximately a l0 inch stroke of the hammer from 60 to 75 times per minute, thus delivering about 8400 foot pounds for each blow `or slightly over 500,000 foot pounds per minute. The blow delivered is approximately four tons. The entire unit weighs about 1875 pounds.

A slight modification of the above device is indicated in FIG. 7 of the drawings. It should be understood that all parts previously described are the same except for the changes about to be indicated.

Power means is provided adapted for remote control whereby the tool 46 may be turned between different positions if desired by the operator. This is particularly useful where a chisel or the like is used for breaking up pavement or other ceramic material. -In FIG. 7, a hydraulic motor 66 is indicated secured to the sleeve 61 in any suitable manner and supplied with hydraulic fluid through the conduit means 67. It is obvious that the conduits might be run back to the control cab where the operator of the boom 53 rides and there provided with control valves. Motor 66 through gear reduction 68 drives shaft 68a rotatably carried by bracket 68h. Rotatable with this shaft is small diameter pinion 69 which meshes with a larger diameter gear 70 which is secured to the anvil shaft 14 so as to turn this shaft and the tool 46 carried at the lower end thereof as shown in FIG. 1A. .Gea-r 70 is held in position by collar 74 and pin 75. Spring 51 performs the same function as spring 51. By control of fluid to motor 66 the operator may slowly rotate tool 46, stopping it in any desired position.

What is claimed is:

1. A blow delivering device comprising a housing having first and second end walls with the axis of said housing passing through said end walls; a tool-carrying member having a shaft disposed coaxial with said housing and extending into said housing through said rst end wall; said shaft having an enlarged, blow receiving anvil at its inner end disposed Within said housing; a hammer reciprocatably mounted in said housing between said anvil and said second end wall; said hammer having an elongated extension coaxial with said shaft and extending through said second end Wall; helical spring means telescoped over said extension and disposed between said hammer and said second end wall; power means carried by said housing outside of said second end wall and including means repeatedly retracting said extension and said hammer against the bias of said spring means and then suddenly releasing them in use of said device, thereby permitting said spring means to cause said hammer to deliver sequential blows against said anvil; resilient cushioning means disposed between said anvil and said irst end wall and cushioning the blow of said hammer against said anvil portion; and additional cushioning means disposed between one end of said helical spring means and said hammer and between the other end of said helical spring means and said second end wall to cushion the blow of said hammer against said anvil.

2. A blow delivering device as set forth in claim 1; a collar secured to said shaft outside said housing and limiting the rebound of said anvil inwardly of said housing after each hammer blow; a coil spring surrounding said shaft and disposed between said collar and said first end wall to cushion the rebound of said anvil; said collar having means defining an aperture therein which is axially parallel with said shaft and laterally displaced therefrom; a bar secured to said housing and disposed parallel with said shaft and projecting away from said housing in the direction of said collar, said bar slidably projecting through said aperture in said collar thereby preventing rotary movement of said shaft while allowing axial movement of said shaft.

3. A blow delivering device comprising a housing; a tool-carrying member having a shaft extending into said housing at one end thereof; said shaft having a blow receiving anvil portion disposed within said housing; a hammer reciprocatably mounted in said housing for a stroke movement in line with said shaft toward and away from said anvil portion; said hammer having an elongated extension coaxial with said shaft and extending further into said housing away from said hammer and out through the end of said housing opposite said one end; a helical spring means surrounding said extension and disposed between said hammer and said opposite housing end; power means carried by said housing including means repeatedly retracting said extension and said hammer against the bias of said spring means and then suddenly releasing them, in use of said device, thereby permitting said spring means to cause said hammer to deliver sequential blows against said anvil; and stop means carried by said member limiting the rebound movement of said anvil portion inwardly of said housing after each hammer blow; said stop means comprising a collar secured to said shaft outside said housing and limiting the movement of said shaft into said housing; said collar having means defining an aperture therein which is axially parallel with said shaft and laterally displaced therefrom; a bar secured to said housing and disposed parallel with said shaft and projecting away from said housing in the direction of said collar; said bar slidably projecting through said aperture in said collar thereby preventing rotary movement of said shaft While allowing axial movement of said shaft.

4. A blow delivering device comprising a housing; a tool-carrying member having a shaft extending into said housing at one end thereof; said shaft Ihaving a blow receiving anvil portion disposed within said housing; a

hammer reciprocatably mounted in said housing for a stroke movement in line with said shaft toward and away from said anvil portion; said hammer having an elongated extension coaxial with said shaft and extending further into said housing away from said hammer and out through the end of said housing opposite said one end; a helical spring means surrounding said extension and disposed between said lhammer and said opposite housing end; power means carried by said housing including means repeatedly retracting said extension and said hammer against the bias of said spring means and then suddenly releasing them, in use of said device, thereby permitting said spring means to cause said hammer to deliver sequential blows against said anvil; and stop means carried by said member limiting the rebound movement of said anvil portion inwardly of said housing after each hammer blow; said stop means comprising a gear secured to said shaft outside said housing and limiting the movement of said shaft into said housing, a pinion rotatably mounted on said housing and meshing with said gear during axial movement of said shaft, and means controlling rotation of said pinion, whereby said gear and shaft may be held in fixed orientation or said shaft may be rotated about its own axis.

References Cited by the Examiner UNITED STATES PATENTS 1,118,692 11/1914 Sone 173-123 X 1,267,174 5/1918 Bert 173-123 X 1,521,979 1/1925 Yamanouchi 173-132 2,201,023 5/1940 Brown 173-119 X 2,436,450 2/1948 Price 173-139 2,672,677 3/ 1954 Von Arx 29-81 2,776,539 1/1957 Pearson 173-123 X 2,812,162 11/1957 Lay 173-44 X 2,936,743 5/1960 Colgate 1'73-128 3,033,297 5/1962 Hall 173-44 X 3,053,100 3/1963 Luhm 173-119 X 3,082,741 3/1963 Huffman 173-105 X BROUGHTON G. DURHAM, Primary Examiner.

L. P. KESSLER, Assistant Examiner. 

4. A BLOW DELIVERING DEVICE COMPRISING A HOUSING; A TOOL-CARRYING MEMBER HAVING A SHAFT EXTENDING INTO SAID HOUSING AT ONE END THEREOF; SAID SHAFT HAVING A BLOW RECEIVING ANVIL PORTION DISPOSED WITHIN SAID HOUSING; A HAMME%R RECIPROCATABLY MOUNTED IN SAID HOUSING FOR A STROKE MOVEMENT IN LINE WITH SAID SHAFT TOWARDD AND AWAY FROM SAID ANVIL PORTION; SAID HAMMER HAVING AN ELONGATED EXTENSION COAXIAL WITH SAID SHAFT AND EXTENDING FURTHER INTO SAID HOUSING AWAY FROM SAID HAMMER AND OUT THROUGH THE END OF SAID HOUSING OPPOSITE SAID ONE END; A HELICAL SPRING MEANS SURROUNDING SAID EXTENSION AND DISPOSED BETWEEN SAID HAMMER AND SAID OPPOSITE HOUSING END; POWER MEANS CARRIED BY SAID HOUSING INCLUDING MEANS REPEATEDLY RETRACTING SAID EXTENSION AND SAID HAMMER AGAINST THE BIAS OF SAID SPRING MEANS AND THEN SUDDENLY RELEASING THEM, IN USE OF SAID DEVICE, THEREBY PERMITTING SAID SPRING 